Because hereditary hemochromatosis (HH) is a disease of iron overload, a review of the basic principles of iron metabolism is helpful in understanding its pathophysiology.

Iron is needed by all body cells and is crucial for oxygen transport, oxidative metabolism, and cell growth and proliferation. To serve these functions, iron must be bound to protein. Iron is potentially harmful when ionized or complexed to inorganic compounds. Iron must be present in amounts sufficient to carry out these normal functions, but not in excessive amounts which may be toxic.

Two types of iron-containing compounds are normally found in the body: compounds that serve in metabolic or enzymatic functions and storage compounds. Hemoglobin, myoglobin, cytochromes and other proteins are involved in oxygen transport and utilization. Iron in hemoglobin comprises about 67% of total body iron, thus erythrocytes are rich in iron. Approximately 27% of iron is found in storage compounds. Myoglobin, other tissue iron, and transport iron comprise the remaining 6% of total body iron. (2)